Theory and Applications of Chemistry Vol. 1

The presence of dyes and heavy metals in water is undesirable and may be toxic to the aquatic environment. Therefore, removal of these contaminants is an important aspect of waste water treatment. Fruit peel was produced by restaurants, fruit juice producers, fruit seller, consumer and food industries in the world. Because of for most fruits, only the fleshy pulps are consumed leaving and the peels were discarded. As a result, these peels causing pollution and serious environmental impact. Therefore, there is the need for an intensified research in the development of the activated carbon. Fruit peels were used as precursor to synthesis activated carbon in water treatment. The obtained activated carbon has higher surface area and pore volume. Equilibrium data will be investigated using Langmuir and Freundlich.

Antimony, cadmium and zirconium hexacyanoferrates (II) were synthesized and characterized by elemental and spectral studies. Interaction of 2, 4-dinitrophenol (2, 4-DNP) and 2, 4, 6-trinitrophenol (2, 4, 6-TNP) with antimony, cadmium and zirconium hexacyanoferrates (II) have been studied at neutral pH (7.00 ± 0.01) and a temperature of 30 ± 1°C. The progress of adsorption was followed spectrophotometrically by measuring the absorbance of substituted phenols at their corresponding λ_max. The nature of adsorption has been interpreted from the shape of adsorption isotherms. The Langmuir type of adsorption is followed in the concentration range of 10^-3 – 10^-4 M of 2, 4-DNP and 2, 4, 6-TNP solutions. The 2, 4, 6 -TNP was found to have greater affinity for the antimony, cadmium and zirconium hexacyanoferrates (II) than 2, 4 – DNP. High adsorption capacity has been observed for cadmium hexacyanoferrate (II) while it is minimum with zirconium hexacyanoferrate (II), which indicate highly porous characteristics of cadmium hexacyanoferrate (II) in comparison to other metal hexacyanoferrates (II) studied. Removal of toxic phenol is necessary for the protection of our environment. Phenols react with soil to reduce their fertility therefore its removal from soil is also important for our food security. The p-nitrophenol was found to have greater affinity for the antimony, cadmium and zirconium ferrocyanides than the p-aminophenol. The adsorption of 2, 4-DNP and 2, 4,6- TNP on copper, zinc, molybdenum and chromium ferrocyanides was studied at different pH and temperature. The thermodynamic parameters for adsorption od 2, 4- DNP and 2, 4, 6- TNP on metal ferrocyanides is reported.

There are many nanostructured thin films (such as binary and ternary compounds) have been prepared using simple chemical bath deposition technique. These films were deposited onto various substrates under different experimental conditions. During the deposition process, complexing agent will be added to improve quality of films. In this work, an analysis was carried out to investigate the growth of films in the presence of complexing agent. Researchers conclude that complexing agent controls cation ions during the deposition process. Aa a result, can produce uniform surface and control deposition rate as well.

The strengths of H-X bond (S_b) of lithium, sodium, beryllium, magnesium, calcium, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen and sulfur were calculated with use of equation ∆_aΨ^o_gas/cond = Σ ∆_atomΨ^o_gas/cond - ∆_fΨ^o_gas/cond  = Σ S_{b gas/cond}, in which were included the functions of free energy and the heats of formation in gaseous and condensed phases. The calculated bond energies of hydrides represent from itself the small magnitudes in a condensed state relatively to the same values in the gaseous phase. One of the reasons it is a small magnitude of the formation of chosen atoms and the formed from they hydrides in a condensed state.

The calculations of strengths of bonds of C-C, C-H, C-O, C=O and O-H bonds of hydrocarbons and carbohydrates with the use of Widows-Excel-function «Search of the decision by a method gradient descent» of condensed carbohydrates of a various spatial structure were made first time. The reduced magnitudes of the force of all bonds in condensed phase, comparing to gas state, designated as a strength of bond (S_b) carbohydrates, necessary to explain by the presence significant hydrogen bonds, dipole-dipole- and dispersive interactions in biochemical  molecules of such type.

Liquid – liquid extraction of Molybdenum (VI) ions from various aqueous medium have been carried out using chloroform solution of 4-adipoylbis (1-phenyl-3-methylpyrazolone-5), H₂Adp and 4-sebacoylbis (1-phenyl-3-methylpyrazolone-5), H₂SP in acid media (HCl, H₂SO₄ and HNO₃) in the presence and absence of butanol as a synergist and also in the presence of the corresponding acids (HCl and H₂SO₄). Optimal extraction was better in HCl followed by HNO₃ and least in H₂SO₄ concentrations. Introduction of butanol into the organic phase resulted in enhanced extraction of Mo(VI) to above 98% using both ligands in all three acid media for both H₂Adp and H₂SP. Statistical treatment using slope analysis show that the extracted specie is M_OO₂ (SP)_(o) and M_OO₂(Adp)_(o).

The effect of the anions, Cl^-, SO₄^2- , Br^- , I^- , SCN^-, PO₄^3-, EDTA, Oxalate, acetate and tartarate on the extraction of Mo (VI) into chloroform solutions of 4-adipoylbis (1-phenyl-3methylpyrazolone-5), H₂Adp and 4-sebacoylbis (1- phenyl-3-methylpyrazolone-5), H₂SP were studied.  The results showed that the masking effect of the halides on the extraction of Mo (VI) followed the increasingly order Cl^-<Br^-<I^-. The trend follows the direction of decrease in electro negativity. Similarly, the extraction of Mo(IV) is increasingly masked with increase in concentration of the complexing agents, decreasing the % extraction from as high as 60% extraction at 10^-3M ligand concentration to as low as10% at 1M ligand concentration.  The extraction of the metal is greatly enhanced in the presence of their corresponding acid solution by increasing the extraction by as high as 10- 40% and also in the presence of butanol. Under all conditions, H₂SP showed to be a better extractant than H₂Adp. The effect of complexing agents such as, PO₄^3-, acetate, EDTA, oxalate and tartarate on the extraction of Mo (VI) ions appears to be fairly constant for both H₂Adp and H₂SP. The results obtained show that extractions of these metals are increasingly masked as anion concentration increase in the aqueous phase.

This computational study assessed ten density functionals that include CAM-B3LYP, LC-ωPBE, M11,
M11L, MN12L, MN12SX, N12, N12SX, ωB97X, and ωB97XD related to the Def2TZVP basis set
together with the SMD solvation model. These are assessed in calculating the molecular properties
and structure of the pyrrolopyrrole-2-carbaldehyde molecule (PPA) in water. The calculated HOMO
and LUMO of PPA are presented through graphical sketches overlapped to its chemical structure. The
chemical reactivity descriptors for the systems are calculated via the Conceptual Density Functional
Theory. The choice of active sites applicable to nucleophilic, electrophilic as well as radical attacks is
made by linking them with Fukui functions indices, electrophilic and nucleophilic Parr functions, and
the condensed dual descriptor ∆f(r).

An important task of chemistry is to establish patterns of dependence on the property of substances on its composition and structure. That is, any link of atomic and molecular formations exhibit physicochemical properties depending on the given conditions, expressing structural and energetic correspondence as part of a material object. Consequently, the task set requires an in-depth study of the dependence on the micro-macroscopic properties of substances on the nature of its constituent elements with its specific characteristics as a whole. Separate consideration of the structural elements of the micro-macroscopic formation of this system without regard to their interaction, in many cases leads to a distortion of reality. At the same time, substances, according to the statements of M. Faraday, continuously make energy exchange with the environment. The analysis of phase equilibrium carried out by G. Gibbs shows that the state of the system is described by thermodynamic parameters (temperature, pressure, volume, chemical potential, etc.), changes in which determine the conditions of the process. The process is characterized by transfer of energy between material objects to create work (chemical, mechanical, electrical, etc.) and physico-chemical manifestations in the form of heat, light, etc. Identifying the mechanism of energy transfer, the nature of energy storage in material substances is not well understood. For the rational use of different types of energy, fundamental research should be carried out, which requires specific scientific concepts and definitions in the field of atomic-molecular formations. In this question, there remains an inconsistency between individual natural sciences, as well as within the same industry in the interpretation of certain conceptual and terminological definitions of matters. “Chemical individual" represents the elementary lattice of a condensed substance or the minimum group of "chemical elements" connected in the form of chemical, metallic, coordination and intermolecular bonds, which determine the structure, composition and properties of this system. The “chemical individual" defines the mechanism of macrostructure formation, i.e. is the source of certain chemical information that affects the structure of the final reaction products. The amount of a substance will allow one to study reactions using the chemical formulas of the reacting substances, to compile stoichiometric and kinetic equations in accordance with their "chemical equivalents". A chemical formula is a conditional notation depicting the elemental composition of a substance with the help of symbols of chemical elements. Because of the identity of the elemental composition of the "elementary chemical compound" and "substance" usually the latter is called a chemical compound, not turning to the micro-macro levels of material formations.

The need for clean and safe consumable water is of paramount importance to any society since water is a crucial substance for the sustenance of life. Kibera slum is one of the leading slums in the world with a high population, leading to poor levels of sanitation and inadequate clean water supply. Consequently, the residents have to seek for alternative water supply. Motoine River flows through the slum, and thus acts as an alternative source of water. This study determined the concentration levels of heavy metals (Pb, Fe, Cu, Cr and Cd) and nutrients (nitrates, nitrites and phosphates) in Motoine River, Kibera in September 2014 and compared the variations downstream. The metals were determined using Atomic Absorption Spectroscopy (AAS) while the nutrients were determined using UV/Visible spectroscopy. Concentration levels of Cu, Cd and Cr were found to be lower than the Environmental Protection Agency (EPA) values for maximum contaminant level (MCL) while those of Fe, Pb and the nutrients were higher than EPA’s MCL values. Cd had the lowest concentration and was below the detection limit of the instrument used. Nitrates were found to be of the highest concentration at 16.4959 ± 2.4432 parts per million (ppm). The high concentration of nutrients in the water could be due to domestic waste and effluent disposal into the river and agricultural runoffs while that of metal ions could be due to waste from informal industries and erosion of natural deposits. The efforts by the government to rehabilitate and clean rivers within Nairobi should be extended to include Motoine River.

This work is aimed at improving the ability of red mud to remove methylene blue from aqueous solution. The efficiency of methylene blue (MB) removal by untreated red mud was compared to that of red mud neutralized with distilled water. The pH, surface charge, particle size distribution, chemical composition, infrared spectrometry and morphology analyses were used to characterize the adsorbents. Batch experiments without agitation and filtration were conducted to determine the influence of contact time, solution pH, temperature, initial dye concentration, adsorbent dose and presence of Cl^-, SO₄^2-, HPO₄^2- and HCO₃^- on dye removal. Distilled water treated red mud (RMD) had improved adsorbent properties than raw red mud (RM). For all the parameters tested, RMD showed higher removals of MB compared to RM. The fitting order for tested isotherm models was: Langmuir > Dubinin–Radushkevich > Freundlich for RMD and Freundlich > Dubinin–Radushkevich > Langmuir for RM. Monolayer adsorption capacities of RMD and RM were found to be 17.123 and 4.221 mg/L respectively. Pseudo-second-order kinetic model suited well than other tested kinetic models. Equilibrium was attained in 24 hours, and the order of shifting of equilibrium to the right as well as the rate of uptake is: MB on RMD > MB on RM. MB removal was found to be more endothermic, more spontaneous and more favourable on RMD than on RM. Desorption experiments using acetone gave good results up to four cycles. MB can easily be removed from waste water using distilled water neutralized red. Water modified red mud is relatively efficient as other used materials for MB removal (Table 5), so it was concluded that red mud modified with distilled water can be used for industrial applications in removing methylene blue from various real effluents released from various types of industries such as chrome plating, textile dyeing, leather tanning and photolithographic industries. Furthermore, red mud is very cheap as compared to other adsorbents so easily available. Also modification of red mud with water is a cheaper process with no risk of introducing other chemicals on to it as opposed to other neutralization methods that use mineral acid, heat and other chemicals. Distilled water neutralized red mud is more efficient in removing methylene blue from waste water than untreated red mud.